chore: import upstream snapshot with attribution

2026-07-13 12:36:30 +08:00
commit 55ab4e4a73
473 changed files with 72932 additions and 0 deletions
@@ -0,0 +1,77 @@
+from itertools import combinations
+
+import easygraph as eg
+
+from easygraph.utils.exception import EasyGraphError
+
+
+__all__ = [
+    "star_clique",
+]
+
+
+def star_clique(n_star, n_clique, d_max):
+    """Generate a star-clique structure
+
+    That is a star network and a clique network,
+    connected by one pairwise edge connecting the centre of the star to the clique.
+    network, the each clique is promoted to a hyperedge
+    up to order d_max.
+
+    Parameters
+    ----------
+    n_star : int
+        Number of legs of the star
+    n_clique : int
+        Number of nodes in the clique
+    d_max : int
+        Maximum order up to which to promote
+        cliques to hyperedges
+
+    Returns
+    -------
+    H : Hypergraph
+
+    Examples
+    --------
+    >>> import easygraph as eg
+    >>> H = eg.star_clique(6, 7, 2)
+
+    Notes
+    -----
+    The total number of nodes is n_star + n_clique.
+
+    """
+
+    if n_star <= 0:
+        raise ValueError("n_star must be an integer > 0.")
+    if n_clique <= 0:
+        raise ValueError("n_clique must be an integer > 0.")
+    if d_max < 0:
+        raise ValueError("d_max must be an integer >= 0.")
+    elif d_max > n_clique - 1:
+        raise ValueError("d_max must be <= n_clique - 1.")
+
+    nodes_star = range(n_star)
+    nodes_clique = range(n_star, n_star + n_clique)
+    nodes = list(nodes_star) + list(nodes_clique)
+
+    H = eg.Hypergraph(num_v=len(nodes))
+
+    # add star edges (center of the star is 0-th node)
+    H.add_hyperedges([[nodes_star[0], nodes_star[i]] for i in range(1, n_star)])
+
+    # connect clique and star by adding last star leg
+    H.add_hyperedges([nodes_star[0], nodes_clique[0]])
+
+    # add clique hyperedges up to order d_max
+
+    H.add_hyperedges(
+        [
+            e
+            for d in range(1, d_max + 1)
+            for e in list(combinations(nodes_clique, d + 1))
+        ]
+    )
+
+    return H